I obviously understand why Studio Pierrot is bringing back sd rock lee, cus of the amount of dough they get for it. But why couldn't they use their budget to work on other shows they stopped abruptly that people are eagerly anticipating to come back like

Beelzebub

Bleach

Or perhaps reanimate

GTO

Yu Yu Hakusho

What shows would you rather see Studio Pierrot bring back or start on instead of SD Rock Lee and his ninja pals?

But yeah the shows you mentioned would be way cooler, though they didn't do a good job with the Beelzebub adaptation imo. I liked it but they almost made it almost as kiddy as the Toriko anime. It would still be better than having no Beelzebub though.

If I had to guess maybe it's place in the ratings and cost to make the show made sense business wise. Maybe the all important home release sales went well.

We have to remember it's all about money if the show does bad in the ratings and sells bad no more anime. Or even if it does great in the ratings and falls short in DVD sells because people rather download it rather than pay= no more anime.

Even though you already answered your own question on the first line. First of all they're not going to remake those two anime just because you like them. It's a long thing where they have to find new VAs if they've already died and all that stuff. It also matters about the fanbase and if they actually want a remake. If fans are content with the past stuff, why make new stuff. Reruns are cheaper than redoing a whole series.
And why would they bring back Bleach when it doesn't have much material. So they can riddle it with fillers and bring down the ratings more?
Beelzelbub is in a similar situation as Bleach but would have to do a remake because the anime changed so much. And you're acting like this means they won't ever make those, this is probably going to have the same amount of episodes as the other season, hope for your shows is not lost.

OT: I am personally completely fine with them bringing back the Rock Lee spinoff and not any of those others. It was really funny and was made funnier by being based off of Naruto.

No, Bleach was canceled because of how close it got to the Manga. With the start of the Thousand Year Blood War and the ratings on the manga, it makes total sense to continue bleach business wise.
I wonder if they will continue it soon or if it will be gone for ever. If it is then I will just have to hang myself in Studio Pierrot's lounging area.